In this chapter we'll be looking at some more very useful classes in the java.util package but this time they are not collection classes – just a collection of classes. We will also be looking at the facilities provided by classes in the java.util.regex package that implements regular expressions in Java. Support for regular expressions is a very powerful and important addition to Java.
In this chapter you will learn:
How to use the static methods in the Arrays class for filling, comparing, sorting, and searching arrays
How to use the Observable class and the Observer interface to communicate between objects
What facilities the Random class provides
How to create and use Date and Calendar objects
What regular expressions are and how you can create and use them